Swash plate mechanism



56% 16, 1941. R. w. DlNzL SWASH PLATE MECHANISM Filed Dee. s, 1940 Sept. 16, 1941.

R. W. DiNZL SWASH PLATE MECHANISM Filed Deo. 3, 1940 2 Sheets-Sheet 2 afl/1,9

ATTORNEY Figui; and

Patented Sept. 16, 1941 SWASH PLATE MECHANISM Richard W. Dinzl, Westfield, N. J., assigner to l The Watson-Stillman Co., Roselle, N. J., a corporation of New Jersey Application December 3, 1940, 'Serial No. 368,365

` 9 Claims. The present inve'ntion relates more particularly to improvements in a swash plate mecha-I nism for operating a pump and in which the swash element or plate is adjustable to vary its pitch and thereby vary the volume of the pump delivery. An important object of the invention is to provide improved means for vadjusting the pitch of the swash element. :Other objects of the invention will appear hereinafter.

In the-drawings,

Fig. 1 is a longitudinal sectional view of a swash unit and pumpl unit combined and embodying the invention;

F18. 2 is a vertical cross section approximately 'on the line z-z or Fig. 1 end witn the swash element swung to a neutral position; l Fig. 3 is a detail section onthe line 3-3 of Fis. 2;v Fig. 4 is a section onl the linel 4--4vof Fig. 2 with parts broken away and with the swash element in maximum pitch position; l

Fig. 5 is a detail section on the line 5-5 of Fg- 4:

Fig. 6 is a detail section on the line Bf-5 of Fig. 'z is a section on the une 1-1 of Fig. 1'. The swash plate mechanism is enclosed within a casing I, and ahydraulic pump unit 2 is rigidly connected to said. casing in a spaced relation to one end of the casing. Said mechanism includes a shaft 3 rotatably supported at one end by ball bearings 4 borne by the end wall of the vcasing remote from the pump unit and at its opposite end by a ball bearing 5 borne by an intermediate wall 6 of the casing. The bearings 4 are formed and supported to resist endwise thrust upon the shaft. A tubular swash element or hub 1 is mounted upon the shaft for rotationl thereby and also for tiltable adjustment about a transverse yaxis at right, angles to the shaft axis.

The mounting for the swash element comprises a trunnon pin 8 having a tapered medial portion fitted within a tapered transverse bore in the shaft.- Said pin has trunnon ernds projecting from opposite sides oftthe shaft and fitting within bearing bushings 9 secured within diametrical bores in the swash element, as shown in Fig. 5. A cotter pin I0 secures the trunnon pin against` rotation vwithin the shaft bore. An enlarged medial portion of the shaft, extending into the swash element is square in cross section. A drive shaft I I, connected to a power source, not shown, is operatively connected to `the shaft 3 through gears I2, I3, I4 and. I5. Gear I5 is aixed to shaft 3, within the casing I, and the other gearsare housed within an extension I? of the casing. A swash follower member I6 of annular form encircles the swash element or hub 'I. Ball lbearings I1 and I8 between the swash element and follower support thelatter on the swash element. and permit the swash element to rotate relatively to the follower about the axis of shaft 3. The se bearings are formed and supported to resist axial thrust. At diametrically opposite sides thereof the follower has -trunnion projections IS rigid therewith and rotatable within bearing bores in a pair, of i blocks 20. These blocks are supported and retained for sliding in a common horizontal plane by guides 2l rigid with jthe casing. Thereby, the follower is held against vrotation with the swash element I but ismounted for swash rocking movement -by' the swash element.

The pump unit a metal block having pump cylinder bores 23 parallel to tlieaxis of the shaft 3. In the present instance there are five of these bores equally spaced around the-shaft axis. Each v`bore 23 is reciprocable therein through a stuing box 21 .the ladjacent piston 29.

in valved connection, through boresin said block with a pump inlet bore 24 and a pump outlet bore 25. Each cylinder bore has a pump plunger 26 and suitable packing.4 The adjacent end of the casing I is formed with guide cylinders 28 col axial with the bores 23 respectively, and each having a piston 29 reciprocable therein. Each pump plunger has a screw-threaded connection The swash follower I6 is operatively connected with the pistons by pull-and-push rods 3l; Each of the latter has spherical ends, one retained in'a spherical bearing 32 borne by the follower I6 and the opposite end retained in a spherical bearing 33 borne by The bearings 32 are equally spaced around the 4axis of the follower in accordance with the spacing of the pistons around the axis of shaft 3 and the spherical ends of the rods 3| are universally rockable within the bearings 32 and 33; Through the connections described, `the swash rocking of the follower I6 will cause operation of the pump plunger to obtain continuous delivery from the pump unit.

'Provision is made for varying the pitch orthrow of the swash element 1 and its follower I5 and thereby varying the stroke of the Vpump plungers and the delivery from the pump unit.

. Shaft 3 has an axial bore 34 opening through its Y outer end. Near the inner end of this bore the shaft has a pair of longitudinal s1ots 35 diametrically located and opening outward from the 2 includes a body 22 formed of .bore to the exterior of the shaft. A pitch-adjusting plunger 36 'is slidably tted within the bore 34 andextends outward through an opening` inthe casing I .provided with packing 31. VNear its inner end -the plunger.. 36 has a transverse bore within which a cross pin 38 is secured. This pin projects outward through the shaft slots 35 to theexterior of the shaft where it has reduced .ends 39. Slide blocks 40, are pivotally mounted upon .these ends and are operativelyconnected to the swash element 1. For'said operative connection the swash element is formed, at the side thereof remote from the pump unit, with a pair of rigid similar brackets 4I located at opposite sides of the shaft 3. These brackets have straight cam slots 42 in a common plane oblique to the axis of the swash element, and so disposed as to vbe oblique to the axis of the shaft 3 in all positions of the swash element about the Din 6. 'I'he swash element bears a stop 43 engageable with one side of shaft 3 to limit tilting of said element to a position for maximumpitch, and

' .a stop 4'4 to engage the opposite side of the shaft and stop the swash element in neutral position when it is swung in the opposite direction about its pivot 8. The slideblocks 40, borne by the plunger 36, slidably t within said cam slots 42. Thereby shift o f the plunger outward within the bore 34 causes tilting of the swash element to iny creaseits pitch and shift of the plunger inward causes the swash element to be rocked about its pivot 8 to reduce its pitch.

slide |blocks .borne by said plunger, pivotal mountings for said blocks on. the plunger supporting them at diametrically opposite sides of the shaft for rocking about an axisrparallel to said transverse axis of the swash element, the shaft having longitudinal clearance slots for'said block mountings, cam means rigid with the said swashvelement andl forming camslots 'at'opposite sidesv 'of the'shaft and slidably receiving said blocks yand arranged in a, common plane disposed to slope with-'reference to the shaft axis in all posi- -tions. to whichA Athe swash element is rocked,

whereby. longitudinal shift of said plunger along the shaft axis will shift saidblocks with it to act upon said cam means and rock the swash element to change its pitch, and screw means to adjust said plunger along the. shaft. axis and thereby adjust the pitch of the swash element.

2. In a swash pump mechanism including a rotatably mounted shaft, a swash element mounted upon said shaft for rotation thereby and for rockingabout an axis transverse to the shaft axis to vary its pitch, and pump plungers spaced aroundthe shaft axis and operable by the swash element, said shaft having an axial bore, a pitchadjusting plunger mounted for reciprocation along the shaft axis within said bore, cam means rigid withthe said swash element and forming camslots' at opposite sides of the shaft and arranged in a common plane dispo with reference to. the shaft axis in all positions Means are provided for manually adjusting I plunger 36 inward and outward and maintainingits adjustments. At the o'uter end-'fof the plunger there is ascrew-threaded rod coaxial Y' .with-the plungenand'having 'a pull-and-push swivel'conneetion with the plunger including-ball the swash'elementf-withing the' hand-wheel vthevrod. 45 and connected plunger 36 may' b e advanced or retracted,`v in` leither idle or running condition of the swash .'mechanism', to change the pitch ofthe swash element 'Land its follower I6 andl thereby change the stroke of the pump plungers 26. A vertical la pointbetween the sleeve 41 and the said swivel connection; and projects upward through a slot 52 inthe bracket 48. At vits upper end said arm Y. bears a pointer 53` to travel over a# scale'borne i g by a plate, 54 secured -to the upper sideof the vlbracket, toindicate the pitch adjustment.

It will be seen that the invention provides very 'curatelyadjusting .the pitch of the swash ele 'ment. 'I'he'construction of the adjusting means is such las toholdth'e swash element positively' vibrating about its pivot 8.1* What-Iclaim 1.. In a swash mechanism including a rotatablyv v-mounted shaft, `and a swash -element mounted upon said shaft for vrotation thereby'and for rockingy labout `an"axis-transverse to the shaft,

axis to vary its pitch, said shaft'having an-.axial connection permits the A to which the swash element is rockable, and camengagingmeans borne by saidl plunger and projecting transversely vfrom oppositesides thereof to enter said cam slots'an'd cooperatewithwsaid. 4cam means lto rock the swaslrelement to change f v its pitch and thereby change the stroke of saidl pump plungers by shift of the pitch-adjusting 1 plunger' along" theshaft axisg'within said bore,

the shaftbei'ri'g longitudinally slotted Yto `a'ord clearance for said cam-engaging means to reachv I the cam slots. and shift with the pitch-adjusting plungen y f 3. In a swash mechanism 'including'arotatably mounted shaft, and a swash element mounted upon said' shaft for rotation thereby and for arm 51 is 'secured'to the threaded rodl 45,\at i of saidfrod`-.axially,'and` an internally threaded simpleandj conveniently operable means for'ac-4 y l .es in` any selected adjustment and preVeIvltitfl'Qm rocking labout anaxis transverse to the shaft axisv vto vary its pitch, vaV pitch-adjusting element mounted for reciprocation along` the shaft axis and for rotation with the shaft, an operative connection between said pitch-adjusting element y Aand the swash element to change the pitch of the latter by Shift Vof the pitch-adjusting element along the shaft axis,v a1screw-'threaded rod extending in the'direction of the shaft axis, a pull-v and-pushswivel connection between said rod and the pitch-'adjusting element to shiftfthelatter for changing.'y the pitch of the swash `element by shift rotatable member .screwed upon said rod and secured againstaxialmovementirelatively to the4 .shaft,lfor.shifting said rod andpitch-adjusting l pitchfof the swash element'. b yrotation' of said .internally vthreaded member.l j -LfAfswashmechanism comprising. arotatably vl'nountedshaft'havingan axial boreia swash ele- Y ment mounted for rotation aboutjthejaxis of said v .shafti andv connectedI 'to .thef'sh'aft'for Arotation .thereby andfmounted also for rockingabout an axis transverse tothe shaft axis to vary its pitch,. I apitcheadjusting plunger mounted for rciprocaf tion withinsaidfb'ore 'and constantly? supported within-the vbore against displacement transverse'. bore, a pitcheadjusting plunger mounted-'for re.-

lyfOf-'the Shft aXiSffand cammeansrigidly'brne ciprocation along -the shaft axis within said bore, l'

elementto change the byy the swash element and operable by shift'of sed to slope v said pitch-adjusting plunger along the shaft axis to rock the swash element to vary its pitch.

5. A swash mechanism comprising a rotatably mounted shaft having an axial bore, a swash element mounted for rotation about the axis of said shaft and connected to the shaft for rotation thereby and mounted also for rocking about an axis transverse to the shaft axis to vary its pitch, a pitch-adjusting, plunger mounted for reciprocation within said bore and constantly supported within the bore against displacement transversely of the shaft axis, cam means rigidly borne by said swash element, and means borne by said plunger and projecting transversely therefrom to engage said cam means and cooperate therewith to rock the swash element to change its pitch by longitudinal movement of the plunger, the shaft being longitudinally slotted to afford clearance for said cam-engaging means to reach the cam means and permit movement of the cam-engaging means with the plunger.

6. A swash mechanism comprising a rotatably mounted shaft having an axial bore, a swash element mounted for rotation about the axis of said shaft and connected to the shaft for rotation thereby and mounted also for rocking about an axis transverse to the shaft axis to vary its pitch, a pitch-adjusting plunger mounted for reciprocation within said bore and constantly supported within the bore against displacement transversely of the shaft axis, cam means rigidly borne by said swash element and forming a cam slot extending longitudinally in a plane transverse to said shaftaxis, and means borne by said plunger and projecting transversely therefrom into lsaid cam slot to cooperate with the cam means to rock the swash element to change its pitch by longitudinal movement of the plunger.

7. A swash mechanism including a rotatably mounted shaft having an axial bore, a swash element mounted for rotation about the axis of said shaft and connected to the shaft for rotation thereby and mounted also for rocking about an axis transverse to the shaft axis to vary its pitch, a pitch-adjusting plunger mounted for reciprocation within said bore and constantly supported within the bore yagainst displacement transverse- 1y of the shaft axis, an operative connection between said plunger and rock the latter to vary its pitchby movement of the plunger along the bore, and screw means to adjust said plunger along the shaft axis and thereby adjust the pitch of the swash element.

8.- A swash mechanismincluding a rotatably mounted shaft having an axial bore, a swash element mounted for rotation about the axis o'f said shaft and connected to the shaft for rotation thereby and mounted also for rocking about an axis transverse to the shaft axis to vary its pitch, a pitch-adjusting plunger mounted for reciprocation within said bore and constantly supported within the bore against displacement transversely of the'shaft axis, an operative connection hetween said plunger and the swash element to rock the latter to vary its pitch by movementl of the plunger along the bore, aplu'nger-adjusting element mounted for adjustment along the shaft axis, aV push-and-pull swivel connection between said adjusting element and plunger to adjust the plunger back and forth by adjustment of the adjusting element back and forth and permit rotation of the plunger with the shaft relatively to the adjusting element, and screw means to adjust said adjusting element along the lshaft axis to therebyadjust the plunger to change the pitch of `the swash element.

9. In a swash mechanism vthe combination of. a rotatably mounted shaft; a swash element mounted upon said shaft for rotation thereby and for rocking about an axis transverse tothe shaft'axis to vary its pitch, said shaft having an axial bore, al pitch-adjusting plunger mounted for reclprocation along the shaft axis within said bore, a pin extending transversely through the said plunger and through slots in the said shaft, the ends ofA said pin extending beyond opposite sides 'of the shaft, a pair of rigid brackets formed on the swash element at opposite sides of -the shaft. means operatively connecting the projectl ing ends of said transverse pin to said rigid brackets, whereby the longitudinal shift of said plunger along the shaft axis will rock the swash element to changeits pitch, and means to adjust said plunger back and forth along the shaft axis.

RICHARD W. DINzL.

the swash element to 

